Glucometabolism in Kidney Transplant Recipients with and without Posttransplant Diabetes: Focus on Beta-Cell Function

Posttransplant diabetes mellitus (PTDM) is a common complication after kidney transplantation. Pathophysiologically, whether beta-cell dysfunction rather than insulin resistance may be the predominant defect in PTDM has been a matter of debate. The aim of the present analysis was to compare glucometabolism in kidney transplant recipients with and without PTDM. To this aim, we included 191 patients from a randomized controlled trial who underwent oral glucose tolerance tests (OGTTs) 6 months after transplantation. We derived several basic indices of beta-cell function and insulin resistance as well as variables from mathematical modeling for a more robust beta-cell function assessment. Mean ± standard deviation of the insulin sensitivity parameter PREDIM was 3.65 ± 1.68 in PTDM versus 5.46 ± 2.57 in NON-PTDM. Model-based glucose sensitivity (indicator of beta-cell function) was 68.44 ± 57.82 pmol∙min-1∙m-2∙mM-1 in PTDM versus 143.73 ± 112.91 pmol∙min-1∙m-2∙mM-1 in NON-PTDM, respectively. Both basic indices and model-based parameters of beta-cell function were more than 50% lower in patients with PTDM, indicating severe beta-cell impairment. Nonetheless, some defects in insulin sensitivity were also present, although less marked. We conclude that in PTDM, the prominent defect appears to be beta-cell dysfunction. From a pathophysiological point of view, patients at high risk for developing PTDM may benefit from intensive treatment of hyperglycemia over the insulin secretion axis.

Clinical Factors for Predicting Pharmacotherapy in Twin Pregnancies Complicated by Gestational Diabetes Mellitus

Controlling blood glucose levels is the main target in pregnant women with gestational diabetes mellitus (GDM). Twin pregnancies are offered the same screening selection and have the same diagnostic criteria as well as treatment of gestational diabetes as singleton pregnancies, even though the risks for pregnancy complications are increased. The aim of this study was to assess the association between predicting factors, OGTT glucose levels and pharmacotherapy requirements in twin pregnancies with GDM. This retrospective cohort study included 446 GDM patients with twin pregnancies (246 managed with lifestyle modifications and 200 requiring pharmacotherapy) over a time period of 18 years. An evaluation of maternal characteristics and a standardized 75 g oral glucose test (OGGT) for glucose concentrations at fasting, 1 h and 2 h were conduced. OGTT glucose levels at fasting (=0 min, p < 0.01) and 1 h (p < 0.01) were significantly associated with the later requirement of pharmacotherapy. Also, clinical risk factors (pre-pregnancy BMI p < 0.01, multiparity p < 0.05, GDM in previous pregnancy p < 0.01, assisted reproduction p < 0.05) showed a predictive accuracy for insulin therapy in twin pregnancies complicated by GDM, whereas age and chorionicity had no effect. OGTT glucose measures in addition to clinical risk factors are promising variables for risk stratification in mothers with GDM and twin pregnancy.

Oxidation of caspase-8 by hypothiocyanous acid enables TNF-mediated necroptosis

Necroptosis is a form of regulated cell death triggered by various host and pathogen-derived molecules during infection and inflammation. The essential step leading to necroptosis is phosphorylation of the mixed lineage kinase domain-like protein (MLKL) by receptor-interacting protein kinase 3 (RIPK3). Caspase 8 cleaves RIPKs to block necroptosis, so synthetic caspase inhibitors are required to study this process in experimental models. However, it is unclear how caspase-8 activity is regulated in a physiological setting. The active site cysteine of caspases is sensitive to oxidative inactivation, so we hypothesized that oxidants generated at sites of inflammation can inhibit caspase-8 and promote necroptosis. Here, we discovered that hypothiocyanous acid (HOSCN), an oxidant generated in vivo by heme peroxidases including myeloperoxidase and lactoperoxidase, is a potent caspase-8 inhibitor. We found HOSCN was able to promote necroptosis in mouse fibroblasts treated with tumor necrosis factor (TNF). We also demonstrate purified caspase-8 was inactivated by low concentrations of HOSCN, with the predominant product being a disulfide-linked dimer between Cys360 and Cys409 of the large and small catalytic subunits. We show oxidation still occurred in the presence of reducing agents, and reduction of the dimer was slow, consistent with HOSCN being a powerful physiological caspase inhibitor. While the initial oxidation product is a dimer, further modification also occurred in cells treated with HOSCN, leading to higher molecular weight caspase-8 species. Taken together, these findings indicate major disruption of caspase-8 function, and suggest a novel mechanism for the promotion of necroptosis at sites of inflammation.

Software Packages and Tools for the Analysis of Continuous Glucose Monitoring Data

The advancement of technology in the field of glycemic control has led to the widespread use of continuous glucose monitoring (CGM), which can be nowadays obtained from wearable devices equipped with a minimally invasive sensor, that is, transcutaneous needle type or implantable, and a transmitter that sends information to a receiver or smart device for data storage and display. This work aims to review the currently available software packages and tools for the analysis of CGM data. Based on the purposes of this work, 12 software packages have been identified from the literature, published until December 2021, namely: GlyCulator, EasyGV (Easy Glycemic Variability), CGM-GUIDE^© (Continuous Glucose Monitoring Graphical User Interface for Diabetes Evaluation), GVAP (Glycemic Variability Analyzer Program), Tidepool, CGManalyzer, cgmanalysis, GLU, CGMStatsAnalyser, iglu, rGV, and cgmquantify. Comparison of available software packages and tools has been done in terms of main characteristics (i.e., publication year, presence of a graphical user interface, availability, open-source code, number of citations, programming language, supported devices, supported data format and organization of the data structure, documentation, presence of a toy example, video tutorial, data upload and download, measurement-units conversion), preprocessing procedures, data display options, and computed metrics; also, each of the computed metrics has been analyzed in terms of its adherence to the American Diabetes Association (ADA) 2017 international consensus on CGM data analysis and the ADA 2019 international consensus on time in range. Eventually, the agreement between metrics computed by different software and tools has been investigated. Based on such comparison, usability and complexity of data management, as well as the possibility to perform customized or patients-group analyses, have been discussed by highlighting limitations and strengths, also in relation to possible different user categories (i.e., patients, clinicians, researchers). The information provided could be useful to researchers interested in working in the diabetic research field as to clinicians and endocrinologists who need tools capable of handling CGM data effectively.

TyGIS: improved triglyceride-glucose index for the assessment of insulin sensitivity during pregnancy

Background

The triglyceride-glucose index (TyG) has been proposed as a surrogate marker of insulin resistance, which is a typical trait of pregnancy. However, very few studies analyzed TyG performance as marker of insulin resistance in pregnancy, and they were limited to insulin resistance assessment at fasting rather than in dynamic conditions, i.e., during an oral glucose tolerance test (OGTT), which allows more reliable assessment of the actual insulin sensitivity impairment. Thus, first aim of the study was exploring in pregnancy the relationships between TyG and OGTT-derived insulin sensitivity. In addition, we developed a new version of TyG, for improved performance as marker of insulin resistance in pregnancy.

Methods

At early pregnancy, a cohort of 109 women underwent assessment of maternal biometry and blood tests at fasting, for measurements of several variables (visit 1). Subsequently (26 weeks of gestation) all visit 1 analyses were repeated (visit 2), and a subgroup of women (84 selected) received a 2 h-75 g OGTT (30, 60, 90, and 120 min sampling) with measurement of blood glucose, insulin and C-peptide for reliable assessment of insulin sensitivity (PREDIM index) and insulin secretion/beta-cell function. The dataset was randomly split into 70% training set and 30% test set, and by machine learning approach we identified the optimal model, with TyG included, showing the best relationship with PREDIM. For inclusion in the model, we considered only fasting variables, in agreement with TyG definition.

Results

The relationship of TyG with PREDIM was weak. Conversely, the improved TyG, called TyGIS, (linear function of TyG, body weight, lean body mass percentage and fasting insulin) resulted much strongly related to PREDIM, in both training and test sets (R² > 0.64, p < 0.0001). Bland–Altman analysis and equivalence test confirmed the good performance of TyGIS in terms of association with PREDIM. Different further analyses confirmed TyGIS superiority over TyG.

Conclusions

We developed an improved version of TyG, as new surrogate marker of insulin sensitivity in pregnancy (TyGIS). Similarly to TyG, TyGIS relies only on fasting variables, but its performances are remarkably improved than those of TyG.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01649-8.

Unraveling the Factors Determining Development of Type 2 Diabetes in Women With a History of Gestational Diabetes Mellitus Through Machine-Learning Techniques

Gestational diabetes mellitus (GDM) is a type of diabetes that usually resolves at the end of the pregnancy but exposes to a higher risk of developing type 2 diabetes mellitus (T2DM). This study aimed to unravel the factors, among those that quantify specific metabolic processes, which determine progression to T2DM by using machine-learning techniques. Classification of women who did progress to T2DM (labeled as PROG, n = 19) vs. those who did not (labeled as NON-PROG, n = 59) progress to T2DM has been performed by using Orange software through a data analysis procedure on a generated data set including anthropometric data and a total of 34 features, extracted through mathematical modeling/methods procedures. Feature selection has been performed through decision tree algorithm and then Naïve Bayes and penalized (L2) logistic regression were used to evaluate the ability of the selected features to solve the classification problem. Performance has been evaluated in terms of area under the operating receiver characteristics (AUC), classification accuracy (CA), precision, sensitivity, specificity, and F1. Feature selection provided six features, and based on them, classification was performed as follows: AUC of 0.795, 0.831, and 0.884; CA of 0.827, 0.813, and 0.840; precision of 0.830, 0.854, and 0.834; sensitivity of 0.827, 0.813, and 0.840; specificity of 0.700, 0.821, and 0.662; and F1 of 0.828, 0.824, and 0.836 for tree algorithm, Naïve Bayes, and penalized logistic regression, respectively. Fasting glucose, age, and body mass index together with features describing insulin action and secretion may predict the development of T2DM in women with a history of GDM.

Temporal Patterns of Glucagon and Its Relationships with Glucose and Insulin following Ingestion of Different Classes of Macronutrients

Background: glucagon secretion and inhibition should be mainly determined by glucose and insulin levels, but the relative relevance of each factor is not clarified, especially following ingestion of different macronutrients. We aimed to investigate the associations between plasma glucagon, glucose, and insulin after ingestion of single macronutrients or mixed-meal. Methods: thirty-six participants underwent four metabolic tests, based on administration of glucose, protein, fat, or mixed-meal. Glucagon, glucose, insulin, and C-peptide were measured at fasting and for 300 min following food ingestion. We analyzed relationships between time samples of glucagon, glucose, and insulin in each individual, as well as between suprabasal area-under-the-curve of the same variables (ΔAUC_GLUCA, ΔAUC_GLU, ΔAUC_INS) over the whole participants’ cohort. Results: in individuals, time samples of glucagon and glucose were related in only 26 cases (18 direct, 8 inverse relationships), whereas relationship with insulin was more frequent (60 and 5, p < 0.0001). The frequency of significant relationships was different among tests, especially for direct relationships (p ≤ 0.006). In the whole cohort, ΔAUC_GLUCA was weakly related to ΔAUC_GLU (p ≤ 0.02), but not to ΔAUC_INS, though basal insulin secretion emerged as possible covariate. Conclusions: glucose and insulin are not general and exclusive determinants of glucagon secretion/inhibition after mixed-meal or macronutrients ingestion.

Mathematical model of insulin kinetics accounting for the amino acids effect during a mixed meal tolerance test

Amino acids (AAs) are well known to be involved in the regulation of glucose metabolism and, in particular, of insulin secretion. However, the effects of different AAs on insulin release and kinetics have not been completely elucidated. The aim of this study was to propose a mathematical model that includes the effect of AAs on insulin kinetics during a mixed meal tolerance test. To this aim, five different models were proposed and compared. Validation was performed using average data, derived from the scientific literature, regarding subjects with normal glucose tolerance (CNT) and with type 2 diabetes (T2D). From the average data of the CNT and T2D people, data for two virtual populations (100 for each group) were generated for further model validation. Among the five proposed models, a simple model including one first-order differential equation showed the best results in terms of model performance (best compromise between model structure parsimony, estimated parameters plausibility, and data fit accuracy). With regard to the contribution of AAs to insulin appearance/disappearance (k_AA model parameter), model analysis of the average data from the literature yielded 0.0247 (confidence interval, CI: 0.0168 - 0.0325) and -0.0048 (CI: -0.0281 - 0.0185) μU·ml^-1/(μmol·l^-1·min), for CNT and T2D, respectively. This suggests a positive effect of AAs on insulin secretion in CNT, and negligible effect in T2D. In conclusion, a simple model, including single first-order differential equation, may help to describe the possible AAs effects on insulin kinetics during a physiological metabolic test, and provide parameters that can be assessed in the single individuals.

Flash Glucose Monitoring to Assess Glycemic Control and Variability in Hemodialysis Patients: The GIOTTO Study

Background: Flash glucose monitoring (FGM) is a technology with considerable differences compared to continuous glucose monitoring (CGM), but it has been scarcely studied in hemodialysis patients. Thus, we aimed assessing the performance of FGM in such patients by comparison to self-monitoring of blood glucose (SMBG). We will also focus on estimation of glycemic control and variability, and their relationships with parameters of glucose homeostasis.

Methods: Thirty-one patients (20 with type 2 diabetes, T2DM, 11 diabetes-free, NODM) collected readings by FGM and SMBG for about 12 days on average. Readings by FGM and SMBG were compared by linear regression, Clarke error grid, and Bland-Altman analyses. Several indices of glycemic control and variability were computed. Ten patients also underwent oral glucose tolerance test (OGTT) for assessment of insulin sensitivity/resistance and insulin secretion/beta-cell function.

Results: Flash glucose monitoring and SMBG readings showed very good agreement in both T2DM and NODM (on average, 97 and 99% of readings during hemodialysis in A+B Clarke regions, respectively). Some glycemic control and variability indices were similar by FGM and SMBG (p = 0.06–0.9), whereas others were different (p = 0.0001–0.03). The majority of control and variability indices were higher in T2DM than in NODM, according to both FGM and SMBG (p = 0.0005–0.03). OGTT-based insulin secretion was inversely related to some variability indices according to FGM (R < −0.72, p < 0.02).

Conclusions: Based on our dataset, FGM appeared acceptable for glucose monitoring in hemodialysis patients, though partial disagreement with SMBG in glycemic control/variability assessment needs further investigations.

Detection of hysteroscopic fluid in the pouch of Douglas: a prospective cohort study about the predictability of bilateral tubal occlusion

Purpose

To determine whether an increase in cul de sac (CDS) fluid after hysteroscopy is predictive of tubal patency.

Methods

In a prospective clinical cohort study, 115 subfertile women undergoing laparoscopic and hysteroscopic surgery at the Medical University of Vienna were invited to participate. The primary outcome was determining whether an increase in fluid in the pouch of Douglas was reflective of unilateral or bilateral tubal patency. Vaginal sonography before and after hysteroscopy was performed to detect fluid in the pouch of Douglas, directly followed by laparoscopy with chromopertubation.

Results

Laparoscopic chromopertubation revealed bilateral Fallopian tube occlusion in 28 women (24.3%). Twenty-seven/40 patients (67.5%) with no fluid shift had bilateral occlusion during the consecutive laparoscopy (p < 0.001). One/75 patients (1.3%) showing a fluid shift had bilateral occlusion (sensitivity of a present fluid shift for uni- or bilateral patency 85.1%, 95% CI: 81.7–99.9, specificity: 96.4%, 95% CI: 75.8–91.8). Intracavitary abnormalities (odds ratio, OR, 0.038; p = 0.030) and adhesions covering one or both tubes (OR 0.076; p = 0.041) increased the risk for a false abnormal result, i.e., uni- or bilateral tubal patency despite the lack of a fluid shift.

Conclusion

When CDS fluid does not change after hysteroscopy, this is a sensitive test for tubal occlusion and further testing may be warranted. However, if there is an increase in CDS fluid after hysteroscopy, particularly for a patient without fluid present prior, this is both sensitive and specific for unilateral or bilateral tubal patency.

Mathematical Model of Glucagon Kinetics for the Assessment of Insulin-Mediated Glucagon Inhibition During an Oral Glucose Tolerance Test

Glucagon is secreted from the pancreatic alpha cells and plays an important role in the maintenance of glucose homeostasis, by interacting with insulin. The plasma glucose levels determine whether glucagon secretion or insulin secretion is activated or inhibited. Despite its relevance, some aspects of glucagon secretion and kinetics remain unclear. To gain insight into this, we aimed to develop a mathematical model of the glucagon kinetics during an oral glucose tolerance test, which is sufficiently simple to be used in the clinical practice. The proposed model included two first-order differential equations -one describing glucagon and the other describing C-peptide in a compartment remote from plasma - and yielded a parameter of possible clinical relevance (i.e., S_GLUCA(t), glucagon-inhibition sensitivity to glucose-induced insulin secretion). Model was validated on mean glucagon data derived from the scientific literature, yielding values for S_GLUCA(t) ranging from -15.03 to 2.75 (ng of glucagon·nmol of C-peptide^-1). A further validation on a total of 100 virtual subjects provided reliable results (mean residuals between -1.5 and 1.5 ng·L^-1) and a negative significant linear correlation (r = -0.74, p < 0.0001, 95% CI: -0.82 - -0.64) between S_GLUCA(t) and the ratio between the areas under the curve of suprabasal remote C-peptide and glucagon. Model reliability was also proven by the ability to capture different patterns in glucagon kinetics. In conclusion, the proposed model reliably reproduces glucagon kinetics and is characterized by sufficient simplicity to be possibly used in the clinical practice, for the estimation in the single individual of some glucagon-related parameters.

Insulin clearance is altered in women with a history of gestational diabetes progressing to type 2 diabetes

BACKGROUND AND AIMS

Insulin clearance is a relevant process in glucose homeostasis. In this observational study, we aimed to assess insulin clearance (Cl_INS) in women with former gestational diabetes (fGDM) both early after delivery and after a follow-up.

METHODS AND RESULTS

We analysed 59 fGDM women, and 16 women not developing GDM (CNT). All women underwent an oral glucose tolerance test (OGTT) yearly, and an insulin-modified intravenous glucose tolerance test (IVGTT) at baseline and at follow-up end (until 7 years). Both IVGTT and OGTT Cl_INS was assessed as insulin secretion to plasma insulin ratio. We also defined IVGTT first (0-10 min) and second phase (10-180 min) Cl_INS. We found that 14 fGDM women progressed to type 2 diabetes (PROG), whereas 45 women remained diabetes-free (NONPROG). At baseline, IVGTT Cl_INS showed alterations in PROG, especially in second phase (0.88 ± 0.10 l·min^-1 in PROG, 0.60 ± 0.06 in NONPROG, 0.54 ± 0.07 in CNT, p ≤ 0.03). Differences in Cl_INS were not found from OGTT. Cox regression analysis showed second phase Cl_INS as significant type 2 diabetes predictor (hazard ratio = 1.90, 95% confidence interval 1.09-3.30, p = 0.02).

CONCLUSION

This study showed that insulin clearance derived from an insulin-modified IVGTT is notably altered in women with history of GDM progressing towards type 2 diabetes.

Glucose Effectiveness from Short Insulin-Modified IVGTT and Its Application to the Study of Women with Previous Gestational Diabetes Mellitus

BACKGROUND

This study aimed to design a simple surrogate marker (i.e., predictor) of the minimal model glucose effectiveness (S_G), namely calculated S_G (CS_G), from a short insulin-modified intravenous glucose tolerance test (IM-IVGTT), and then to apply it to study women with previous gestational diabetes mellitus (pGDM).

METHODS

CS_G was designed using the stepwise model selection approach on a population of subjects (n=181) ranging from normal tolerance to type 2 diabetes mellitus (T2DM). CS_G was then tested on a population of women with pGDM (n=57). Each subject underwent a 3-hour IM-IVGTT; women with pGDM were observed early postpartum and after a follow-up period of up to 7 years and classified as progressors (PROG) or non-progressors (NONPROG) to T2DM. The minimal model analysis provided a reference S_G.

RESULTS

CS_G was described as CS_G=1.06×10⁻²+5.71×10⁻²×K_G/G_peak, K_G being the mean slope (absolute value) of loge glucose in 10-25- and 25-50-minute intervals, and G_peak being the maximum of the glucose curve. Good agreement between CS_G and S_G in the general population and in the pGDM group, both at baseline and follow-up (even in PROG and NONPROG subgroups), was shown by the Bland-Altman plots (<5% observations outside limits of agreement), and by the test for equivalence (equivalence margin not higher than one standard deviation). At baseline, the PROG subgroup showed significantly lower S_G and CS_G values compared to the NONPROG subgroup (P<0.03).

CONCLUSION

CS_G is a valid S_G predictor. In the pGDM group, glucose effectiveness appeared to be impaired in women progressing to T2DM.

Former gestational diabetes: Mathematical modeling of intravenous glucose tolerance test for the assessment of insulin clearance and its determinants

Women with a previous history of gestational diabetes mellitus (GDM) have increased risk of developing GDM in future pregnancies (i.e. recurrent GDM) and also Type 2 Diabetes (T2D). Insulin clearance represents one of the processes regulating glucose tolerance but has been scarcely investigated for its possible impairment in high-risk subjects. The aim of this study was to identify possible determinants of insulin clearance in women with a previous history of GDM. A detailed model-based analysis of a regular 3-hour, insulin-modified intravenous glucose tolerance test (IM-IVGTT) has been performed in women with a previous history of GDM (pGDM, n = 115) and in women who had a healthy pregnancy (CNT, n = 41) to assess total, first-phase and second-phase insulin clearance (Cl_INS-TOT, Cl_INS-FP and Cl_INS-SP) and other metabolic parameters (insulin sensitivity S_I, glucose effectiveness S_G, beta-cell function and disposition index DI). CL_INS-SP was found increased in pGDM with respect to CNT and was found significantly inversely linearly correlated with S_G (r = -0.20, p = 0.03, slope: -16.2, 95% CI -30.9 to -1.4, intercept: 1.1, 95% CI 0.7-1.4) and also with DI (r = -0.22, p = 0.02, slope: -10.0, 95% CI -18.5 to -1.6, intercept: 0.9, 95% CI 0.7-1.3). Disposition index, accounting for the combined contribution of insulin sensitivity and beta-cell function, and glucose effectiveness were identified as possible determinants of insulin clearance in women with a previous history of GDM. This may be of relevance for more accurate estimation and prevention of the risk for recurrent GDM and T2D.

Glucose effectiveness and its components in relation to body mass index

BACKGROUND

Obesity is known to induce a deterioration of insulin sensitivity (S_I ), one of the insulin-dependent components of glucose tolerance. However, few studies investigated whether obesity affects also the insulin-independent component, that is glucose effectiveness (S_G ). This cross-sectional study aimed to analyse S_G and its components in different body mass index (BMI) categories.

MATERIALS AND METHODS

Three groups of subjects spanning different BMI (kg m^-2 ) categories underwent a 3-h frequently sampled intravenous glucose tolerance test: Lean (LE; 18.5 ≤ BMI < 25, n = 73), Overweight (OW; 25 ≤ BMI < 30, n = 90), and Obese (OB; BMI ≥ 30, n = 41). OB has been further divided into two subgroups, namely Obese I (OB-I; 30 ≤ BMI < 35, n = 27) and Morbidly Obese (OB-M; BMI ≥ 35, n = 14). Minimal model analysis provided S_G and its components at zero (GEZI) and at basal (BIE) insulin.

RESULTS

Values for S_G were 1.98 ± 1.30 × 10^-2 ·min^-1 in all subjects grouped and 2.38 ± 1.23, 1.84 ± 0.82, 1.59 ± 0.61 10^-2 ·min^-1 in LE, OW and OB, respectively. In all subjects grouped, a significant inverse linear correlation was found between the log-transformed values of S_G and BMI (r = -0.3, P < 0.0001). S_G was significantly reduced in OW and OB with respect to LE (P < 0.001) but no significant difference was detected between OB and OW (P = 0.35) and between OB-I and OB-M (P = 0.25). Similar results were found for GEZI. BIE was not significantly different among NW, OW and OB (P = 0.11) and between OB-I and OB-M (P ≥ 0.07).

CONCLUSIONS

S_G and its major component GEZI deteriorate in overweight individuals compared to those in the normal BMI range, without further deterioration when BMI increases above 30 kg m^-2 .

Glucagon-like peptide 1 (GLP-1) drives postprandial hyperinsulinemic hypoglycemia in pregnant women with a history of Roux-en-Y gastric bypass operation

BACKGROUND

The influential role of incretin hormones on glucose metabolism in patients with a history of Roux-en-Y gastric bypass (RYGB) has been investigated thoroughly, but there has been little examination of the effect of incretins and ectopic lipids on altered glucose profiles, especially severe hypoglycemia in pregnant women with RYGB.

METHODS

In this prospective clinical study, an oral glucose tolerance test (OGTT), an intravenous glucose tolerance test (IVGTT), and continuous glucose monitoring (CGM) were conducted in 25 women with RYGB during pregnancy, 19 of normal weight (NW) and 19 with obesity (OB) between the 24th and the 28th weeks of pregnancy, and 3 to 6 months post-partum. Post-partum, the ectopic lipid content in the liver, heart, and skeletal muscle was analyzed using ¹H-magnetic resonance spectroscopy (¹H-MRS).

RESULTS

RYGB patients presented with major fluctuations in glucose profiles, including a high occurrence of postprandial hyperglycemic spikes and hypoglycemic events during the day, as well as a high risk of hypoglycemic periods during the night (2.9 ± 1.1% vs. 0.1 ± 0.2% in the OB and vs. 0.8 ± 0.6% in the NW groups, p < 0.001). During the extended OGTT, RYGB patients presented with exaggerated expression of GLP-1, which was the main driver of the exaggerated risk of postprandial hypoglycemia in a time-lagged correlation analysis. Basal and dynamic GLP-1 levels were not related to insulin sensitivity, insulin secretion, or beta cell function and did not differ between pregnant women with and without GDM. A lower amount of liver fat (2.34 ± 5.22% vs.5.68 ± 4.42%, p = 0.015), which was positively related to insulin resistance (homeostasis model assessment of insulin resistance, HOMA-IR: rho = 0.61, p = 0.002) and beta-cell function (insulinogenic index: rho = 0.65, p = 0.001), was observed in the RYGB group after delivery in comparison to the OB group.

CONCLUSION

GLP-1 is mainly involved in the regulation of postprandial glucose metabolism and therefore especially in the development of postprandial hypoglycemia in pregnant RYGB patients, who are characterized by major alterations in glucose profiles, and thus in long-term regulation, multiple organ-related mechanisms, such as the lipid content in the liver, must be involved.

Fertility, Pregnancy and Lactation After Bariatric Surgery - a Consensus Statement from the OEGGG

Bariatric surgery is recommended when other weight loss interventions, such as lifestyle modification or medications, have failed. A considerable number of women undergoing bariatric surgery are of childbearing age; hence, it is necessary to be aware of the effects of bariatric surgery on pregnancy for managing these patients. Although bariatric surgery is associated with positive effects on cardiovascular and metabolic parameters, side effects such as anaemia, the risk of developing internal hernia, altered glucose metabolism and the risk of small for gestational age offspring have to be considered. Pregnant women with a history of gastric bypass should not undergo the oral glucose tolerance test (OGTT) due to the high risk of hypoglycaemia. There are no contraindications for vaginal delivery and breastfeeding. This paper has been published as a consensus statement by the Austrian Society of Gynaecology and Obstetrics (OEGGG).

Assessment of glucose effectiveness from short IVGTT in individuals with different degrees of glucose tolerance

AIMS

Minimal model analysis of intravenous glucose tolerance test (IVGTT) data represents the reference method to assess insulin sensitivity (S_I) and glucose effectiveness (S_G) that quantify the insulin-dependent and insulin-independent processes of glucose disappearance, respectively. However, test duration (3 h) and need for modeling expertise limit the applicability of this method. Aim of this study was providing a simple predictor of S_G applicable to short test (1 h), as previously done with S_I.

METHODS

Three groups of subjects reflecting different glucose tolerance degrees underwent a 3 h IVGTT: subjects with normal glucose tolerance (NGT, n = 164), with defective glucose regulation (DGR, n = 191), and with type 2 diabetes (T2D, n = 39). Minimal model analysis provided reference S_G and its components at zero (GEZI) and basal (BIE) insulin. The simple predictor CS_G (calculated S_G) was described by the formula CS_G = α₀ + α₁ × K_G/G_peak, being K_G the glucose disappearance rate (between 10 and 50 min) and G_peak the maximum of the glucose curve during the test; α₀ and α₁ coefficients were provided by linear regression analysis.

RESULTS

CS_G and S_G showed a markedly significant relationship in the whole dataset (r = 0.72, p < 0.0001) and in the single groups (r = 0.70 in NGT, r = 0.71 in DGR and r = 0.70 in T2D, p < 0.0001 for all); α₁ × K_G/G_peak was significantly related to GEZI (r ≥ 0.60).

CONCLUSIONS

The interest for insulin-independent glucose disappearance is increasing, due to the recent availability of SGLT2 pharmacological agents, lowering glycemic levels without requiring insulin action. This study proposes a reliable predictor of S_G based on IVGTT lasting 1 h only, and not requiring mathematical modeling skills.

Pre- and peripartal management of a woman with McArdle disease: a case report

McArdle disease or glycogen storage disease (GSD) type V is a rare autosomal recessive inherited disorder in skeletal muscle metabolism leading to exercise intolerance, muscle cramps and in some cases to rhabdomyolysis and acute renal failure due to elevated serum myoglobin levels. Albeit the uterine smooth muscle is not affected, pregnancy and delivery can be physically strenuous and may require specific anesthesiologic care. However, data on pregnancy progress and outcome and on special implications linked to anesthesia in women with McArdle's disease is scarce, thus posing a challenge to pre- and peripartal management. We report a case of a pregnant woman with Morbus McArdle who was monitored during her pregnancy and delivered a healthy male via cesarean section under spinal anesthesia. Pregnancy, delivery and recovery were uneventful. Our findings, combined with a literature review, lead to the conclusion that uncomplicated pregnancy and delivery can be expected.

Management of Pregnant Women after Bariatric Surgery

The prevalence of obesity is growing worldwide, and strategies to overcome this epidemic need to be developed urgently. Bariatric surgery is a very effective treatment option to reduce excess weight and often performed in women of reproductive age. Weight loss influences fertility positively and can resolve hormonal imbalance. So far, guidelines suggest conceiving after losing maximum weight and thus recommend conception at least 12-24 months after surgery. As limited data of these suggestions exist, further evidence is urgently needed as well for weight gain in pregnancy. Oral glucose tolerance tests for the diagnosis of gestational diabetes mellitus (GDM) should not be performed after bariatric procedures due to potential hypoglycaemic adverse events and high variability of glucose levels after glucose load. This challenges the utility of the usual diagnostic criteria for GDM in accurate prediction of complications. Furthermore, recommendations on essential nutrient supplementation in pregnancy and lactation in women after bariatric surgery are scarce. In addition, nutritional deficiencies or daily intake recommendations in pregnant women after bariatric surgery are not well investigated. This review summarizes current evidence, proposes clinical recommendations in pregnant women after bariatric surgery, and highlights areas of lack of evidence and the resulting urgent need for more clinical investigations.

Prediction of clamp-derived insulin sensitivity from the oral glucose insulin sensitivity index

AIMS/HYPOTHESIS

The euglycaemic-hyperinsulinaemic clamp is the gold-standard method for measuring insulin sensitivity, but is less suitable for large clinical trials. Thus, several indices have been developed for evaluating insulin sensitivity from the oral glucose tolerance test (OGTT). However, most of them yield values different from those obtained by the clamp method. The aim of this study was to develop a new index to predict clamp-derived insulin sensitivity (M value) from the OGTT-derived oral glucose insulin sensitivity index (OGIS).

METHODS

We analysed datasets of people that underwent both a clamp and an OGTT or meal test, thereby allowing calculation of both the M value and OGIS. The population was divided into a training and a validation cohort (n = 359 and n = 154, respectively). After a stepwise selection approach, the best model for M value prediction was applied to the validation cohort. This cohort was also divided into subgroups according to glucose tolerance, obesity category and age.

RESULTS

The new index, called PREDIcted M (PREDIM), was based on OGIS, BMI, 2 h glucose during OGTT and fasting insulin. Bland-Altman analysis revealed a good relationship between the M value and PREDIM in the validation dataset (only 9 of 154 observations outside limits of agreement). Also, no significant differences were found between the M value and PREDIM (equivalence test: p < 0.0063). Subgroup stratification showed that measured M value and PREDIM have a similar ability to detect intergroup differences (p < 0.02, both M value and PREDIM).

CONCLUSIONS/INTERPRETATION

The new index PREDIM provides excellent prediction of M values from OGTT or meal data, thereby allowing comparison of insulin sensitivity between studies using different tests.

Pericardial Fat Relates to Disturbances of Glucose Metabolism in Women with the Polycystic Ovary Syndrome, but Not in Healthy Control Subjects

OBJECTIVE

The objective of the present study is to investigate the relationship of cardiac fat depots with disturbances of the carbohydrate metabolism in women with PCOS.

METHODS

An oral glucose tolerance test (OGTT) was realized, and metabolic parameters were collected in 48 women with PCOS and in 20 controls. Intramyocardial fat (MYCL) and pericardial fat (PERI) were measured using ¹H-magnetic resonance spectroscopy and imaging.

RESULTS

Only in PCOS women, PERI was positively and independently related to parameters of glucose metabolism (HbA1c: p = 0.001, fasting plasma glucose: p < 0.001, stimulated glucose at 30 and 60 minutes in the OGTT). Thus, the disposition index, insulin sensitivity, and adiponectin also declined with the increase of PERI in women with PCOS; however, these results were not independent of BMI and age. In addition, PERI was positively related to atherogenic lipid profiles, BMI, waist circumference, CRP, and liver fat in women with PCOS. A negative relation of PERI with triglycerides and a positive relation with BMI and waist circumference could be observed in the controls. No relationship of MYCL with diabetes-specific parameters could be found in the study population.

CONCLUSION

PERI is related to metabolic disturbances in women with PCOS, but not in metabolically healthy lean subjects. This clinical trial was registered at ClinicalTrials.gov and has the registration number NCT03204461.

The Fatty Liver Index (FLI) Relates to Diabetes-Specific Parameters and an Adverse Lipid Profile in a Cohort of Nondiabetic, Dyslipidemic Patients

BACKGROUND

Patients with hyperlipidemia are at high risk for developing a fatty liver. The fatty liver index (FLI) is a noninvasive and well-established method for the estimation of a fatty liver. However, little is known about the metabolic characterization of nondiabetic treated patients with hyperlipidemia who have different risk levels for a fatty liver.

METHODS

In this study, 74 nondiabetic patients with hyperlipidemia were divided into 3 groups according to their fatty liver index. A comparison of metabolic characteristics was done. These characteristics included intima media thickness (IMT) and nutritional habits, which were further divided into FLI subgroups with low, intermediate, and high risk for a fatty liver.

RESULTS

Patients with hyperlipidemia, with a high risk for a fatty liver (FLI ≥ 60), had subclinical elevations in parameters of carbohydrate metabolism (insulin, fasting plasma glucose, C-peptide) including a higher insulin resistance (quantitative insulin sensitivity check index, QUICKI) compared to lower FLI groups. These patients also presented a higher risk for a metabolic syndrome (p = 0.018), as well as an adverse lipid profile (e.g., high-density lipoprotein [HDL] cholesterol, triglycerides [TG]-HDL ratio). FLI group 3 was characterized by significantly lower levels of omega-3 fatty acids (p = 0.048).

CONCLUSION

The fatty liver index relates to diabetes-specific parameters and an adverse lipid profile and is an appropriate index for risk evaluation of metabolic syndrome.

Insulin resistance and beta-cell dysfunction in people with prediabetes according to criteria based on glycemia and glycosylated hemoglobin

Impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) are well-known conditions of risk for diabetes. Recently, 1h-hyperglycemia (1h-HG), i.e., glycemia > 8.6 mmol/L, has been suggested as further condition of diabetes risk. Moreover, in 2010 the American Diabetes Association included the measurement of glycosylated hemoglobin (HbA1c) among the criteria of diabetes risk (5.7-6.4%). Aim of this study was investigating all these different conditions of diabetes risk, with specific focus on possible insulin sensitivity and beta-cell function changes, when 1h-HG, and further HbA1c-prediabetes, are added to the already deeply studied condition of IFG/IGT. In this study, we retrospectively analysed 744 participants that underwent 2h-OGTT and HbA1c measurement. Participants were stratified into groups: (i) normal glucose tolerance, NGT (n=178); (ii) IFG and/or IGT (n=88); (iii) IFG/IGT plus 1h-HG (n=342); (iv) IFG/IGT plus 1h-HG plus HbA1c-prediabetes (n=136). We calculated several indices of insulin sensitivity and beta-cell function, as well as an index considering both aspects (disposition index). We found that progressing from group (i) to group (iv) both insulin sensitivity and beta-cell function tended to further deteriorate; the parameter providing more evidence was the disposition index (p<0.008 in any group comparison). In conclusion, for appropriate assessment of the level of diabetes risk (especially in people already known to be at high risk), it may be convenient to measure all the indicated parameters, that is, glycemia at fasting, at one hour and two hours during OGTT, and glycosylated hemoglobin.

[Metabolic and Reproductive Consequences of the Polycystic Ovary Syndrome (PCOS)]

Polycystic ovarian syndrome represents the most common endocrine disease of women of reproductive age. Symptoms include metabolic, gynecologic and cosmetic features. Genetic factors seem to contribute to the disease, affecting not only women but also male relatives of patients with similar symptoms. Besides, lifestyle factors play a central role impacting clinical PCOS appearance. Following we present an overview of the syndrome, its epidemiology, metabolic and gynecological aspects, gender and genetic factors and its therapy.

Reproductive outcome in European and Middle Eastern/North African patients

The aim of this retrospective cohort study was to assess differences in infertility-related baseline characteristics and IVF outcome between European and Middle Eastern/North African (MENA) patients. Of 2703 patients undergoing their first IVF cycle, 2485 were Caucasian of European descent and 218 originated from the MENA region. MENA patients were significantly younger (30.6 versus 34.0 years, P < 0.001), less likely smokers, with higher body mass indexes. Infertility duration was longer in MENA patients (P < 0.001), their male partners were younger (P < 0.001) and smoked more often than European male patients (P = 0.005). Male factor infertility (P = 0.017) and polycystic ovary syndrome (PCOS; P = 0.032) was more prevalent in MENA patients, showed significantly higher basal FSH concentrations (P = 0.012) and significantly fewer oocytes retrieved (RR 0.83, 95% CI 0.74-0.93, P = 0.001). Clinical pregnancy rates were comparable (22.4% [European] versus 22.9% [MENA]). Fewer MENA patients had surplus embryos cryopreserved (OR 0.41, 95% CI 0.22-0.76, P = 0.004). Despite younger age and higher prevalence of PCOS, MENA patients had significantly lower oocyte yields than their European counterparts (P = 0.001). These findings suggest a more rapid decline in ovarian function in women of MENA descent.

Training on an inexpensive tablet-based device is equally effective as on a standard laparoscopic box trainer: A randomized controlled trial

BACKGROUND

The aim of the study was to assess whether an inexpensive tablet-based box trainer (TBT) is at least equally effective compared with a standard box trainer (SBT) to learn basic laparoscopic skills (BLS). BLS training outside the operating room has been shown to be beneficial for surgical residency. However, simulation trainers are expensive and are not consistently available in all training centers. Therefore, TBT and other homemade box trainers were developed.

METHODS

Medical students were randomized to either a TBT or an SBT and trained 4 fundamentals of laparoscopic surgery (FLS) tasks for 1 hour twice a week for 4 weeks. A baseline test before the training period and a posttraining test were performed. All students then completed a questionnaire to assess their assigned box trainer. The primary outcome measure was the improvement in total test scores. Improvement in the scores for the 4 individual FLS tasks was chosen as a secondary outcome measure.

RESULTS

Thirty-two medical students were recruited. Baseline test scores did not differ significantly between the groups. BLS improved significantly in both groups for the total score and for all 4 tasks separately. Participants in the TBT group showed a greater improvement of total scores than those in the SBT group, although this did not reach statistical significance; noninferiority of the TBT compared with the SBT concerning the improvement of total scores could be demonstrated. Regarding the individual FLS tasks, noninferiority of the TBT could be shown for the pattern cutting and the suturing with intracorporeal knot-tying task. The acceptance of the TBT by the trainees was very good.

CONCLUSION

Learning BLS on a homemade TBT is at least equally effective as on an SBT, with the advantage of being very cost saving. Therefore, this readily available box trainer may be used as an effective, flexible training device outside the operating room to improve accessibility to simulation training.

Clinical and metabolic characteristics of treated hyperlipidemic patients additionally affected by subclinical hyperglycemia

Background

Impaired glucose regulation (IGR) and hyperlipidemia (HL) are associated with an increased risk of developing a cardiovascular disease. Hyperlipidemic patients were shown to bear a greater risk for an increased intima media thickness (IMT). However little is known about differences between treated hyperlipidemic patients (HL) with normal (NGR) or impaired (IGR) glucose regulation.

Methods

We performed a cross-sectional study, involving 96 non-diabetic HL patients with IGR (fasting plasma glucose of ≥ 100 mg/dl and <126 mg/dl or/and HbA1c-level of ≥ 5.7 and <6.5 %) or with NGR (HbA1c-level of <5.7 % and a fasting glucose <100 mg/dl). We compared metabolic characteristics and the IMT between the two groups. Insulin sensitivity in fasting conditions was described by HOMA-IR and QUICKI.

Results

HL-IGR patients were older (57.6 ± 10.4 vs. 49.1 ± 8.7, p < 0.001), had higher carotid IMT measurements (IMT average: 0.68 ± 0.14 vs. 0.60 ± 0.09, p = 0.002; IMT right: 0.67 ± 0.15 vs. 0.60 ± 0.10, p = 0.013; IMT left: 0.63 vs. 0.57, p = 0.009), as well as a higher chance to exceed a cut-off value of ≥0.8 mm or insignificant stenosis within this investigation (OR: 3.9, 95 % CI: 1.15-13.22, p = 0.029) compared to HL-NGR-patients. Furthermore HL-IGR patients were characterised by a higher waist circumference (100.6 ± 10.1 vs. 91.6 ± 13.3, p < 0.001), higher fasting plasma glucose-levels (100.1 ± 10.8 vs. 88.1 ± 6.6, p < 0.001), higher HbA1c concentrations (5.8 ± 0.33 vs. 5.3 ± 0.24, p < 0.001) and C-peptide levels (2.70 vs. 2.10, p = 0.012). Age and CVD status were in general the only two variables which independently explained IMT.

Conclusion

Our study showed that among patients with treated hyperlipidemia the presence of IGR characterised subjects who were older and had a significantly higher risk for an increased IMT compared with those maintaining NGR. Further studies are necessary to evaluate if this specific subpopulation with IGR can benefit from a more strict multifactorial management and perhaps from an additional early antihyperglycaemic treatment.

Cardiometabolic Risk in Hyperlipidemic Men and Women

Objective. The aim of this study was to evaluate sex specific differences of metabolic and clinical characteristics of treated hyperlipidemic men and women (HL-men and HL-women). Methods. In this study vascular and metabolic characteristics of 35 HL-women and 64 HL-men were assessed. In addition a sex specific analysis of metabolic and nutritional habits of HL-patients with prediabetes (HL-IGR) was done. Results. HL-women were older and had favourable concentrations of high density lipoprotein cholesterol (HDL-cholesterol), triglycerides (TG), and triglyceride/HDL-cholesterol ratio (TG/HDL-ratio) but were also shown to have higher concentrations of lipoprotein-a compared to HL-men. HL-men were characterized as having higher levels of liver-specific parameters and body weight as well as being more physically active compared to HL-women. Brain natriuretic peptide (pro-BNP) was higher in HL-women than HL-men, while no differences in metabolic syndrome and glycemic parameters were shown. HL-IGR-women were also older and still had a better profile of sex specific lipid parameters, as well as a lower body weight compared to HL-IGR-men. No differences were seen in vascular parameters such as the intima media thickness (IMT). Conclusion. HL-women were older and had overall more favourable concentrations of lipid parameters and liver enzymes but did not differ regarding vascular morphology and insulin sensitivity compared to HL-men of comparable body mass index (BMI).

Fasting and postprandial liver glycogen content in patients with type 1 diabetes mellitus after successful pancreas-kidney transplantation with systemic venous insulin delivery

BACKGROUND

In patients with type 1 diabetes mellitus (T1DM), insulin is usually replaced systemically (subcutaneously) and not via the physiological portal route. According to previous studies, the liver's capacity to store glycogen is reduced in T1DM patients, but it remains unclear whether this is due to hyperglycaemia, or whether the route of insulin supply could contribute to this phenomenon. T1DM patients after successful pancreas-kidney transplantation with systemic venous drainage (T1DM-PKT) represent a suitable human model to further investigate this question, because they are normoglycaemic, but their liver receives insulin from the pancreas transplant via the systemic route.

MATERIALS AND METHODS

In nine T1DM-PKT, nine controls without diabetes (CON) and seven patients with T1DM (T1DM), liver glycogen content was measured at fasting and after two standardized meals employing (13) C-nuclear-magnetic-resonance-spectroscopy. Circulating glucose and glucoregulatory hormones were measured repeatedly throughout the study day.

RESULTS

The mean and fasting concentrations of peripheral plasma glucose, insulin, glucagon and C-peptide were comparable between T1DM-PKT and CON, whereas T1DM were hyperglycaemic and hyperinsulinaemic (P < 0·05 vs T1DM-PKT and CON). Total liver glycogen content at fasting and after breakfast did not differ in the three groups. After lunch, T1DM-PKT and T1DM had a 14% and 21% lower total liver glycogen content than CON (P < 0·02).

CONCLUSION

In spite of normalized glycaemic control, postprandial liver glycogen content was reduced in T1DM-PKT with systemic venous drainage. Thus, not even optimized systemic insulin substitution is able to resolve the defect in postprandial liver glycogen storage seen in T1DM patients.

Insulin resistance is not associated with myocardial steatosis in women

AIMS/HYPOTHESIS

Insulin resistance, an independent risk-factor for cardiovascular disease, precedes type 2 diabetes and is associated with ectopic lipid accumulation in skeletal muscle and liver. Recent evidence indicates that cardiac steatosis plays a central role in the development of diabetic cardiomyopathy. However, it is not known whether insulin resistance as such in the absence of type 2 diabetes is associated with heart steatosis and/or impaired function. We therefore assessed myocardial steatosis and myocardial function in a sample of women with normal insulin sensitivity, insulin resistance, impaired glucose tolerance (IGT) and type 2 diabetes.

METHODS

Magnetic resonance imaging and localised spectroscopy were used to measure left ventricular dynamic variables and myocardial lipid accumulation in interventricular septum of non-diabetic, age- and BMI-matched insulin-sensitive (n = 11, 47 ± 6 years, BMI 25 ± 2 kg/m(2); clamp-like index [CLIX] = 9.7 ± 0.7) and insulin-resistant (n = 10, 48 ± 5 years, 27 ± 4 kg/m(2); CLIX = 4.5 ± 0.4) women with normal glucose tolerance as well as of women with IGT (n = 6, 45 ± 5 years, 28 ± 6 kg/m(2); CLIX = 3.6 ± 1.1) and type 2 diabetes (n = 7, 52 ± 10 years, 27 ± 3 kg/m(2)).

RESULTS

Myocardial lipid content was increased in type 2 diabetic women only (insulin-sensitive 0.4 ± 0.2% [means ± SD]; insulin-resistant 0.4 ± 0.1%; IGT 0.5 ± 0.2%; type 2 diabetes 0.7 ± 0.3%; p < 0.05). In insulin-resistant and type 2 diabetic women, stroke volume was lower (-15% and -27%, respectively, vs insulin-sensitive) and heart rate was higher (11% and 14%, respectively, vs insulin-sensitive, p < 0.05). No other differences in systolic and diastolic function were observed between study groups.

CONCLUSIONS/INTERPRETATION

In contrast to liver and skeletal muscle, insulin resistance as such is not associated with increased myocardial lipid accumulation.

Thyrotropin serum concentrations in patients with papillary thyroid microcancers

BACKGROUND

Recent studies have shown that elevated serum thyrotropin (thyroid-stimulating hormone [TSH]) concentrations are associated with an increased risk of differentiated thyroid cancers in patients with nodular goiter. Therefore, the measurement of TSH concentrations might support the clinical estimation of cancer risk, especially in patients with thyroid nodules that are too small for fine-needle aspiration biopsies. Thus, the objective of this study was to compare preoperative serum TSH concentrations in patients with papillary thyroid microcarcinoma (PTMC) and individuals in whom the presence of even small differentiated thyroid cancers was excluded by thorough histological examination of the thyroid after total thyroidectomy because of medullary thyroid carcinoma or c-cell hyperplasia.

METHODS

The study was a retrospective cross-sectional analysis. Thirty-three patients with PTMC who had undergone a hemi- or total thyroidectomy and 54 subjects with medullary thyroid carcinoma or c-cell hyperplasia in whom a total thyroidectomy had been performed between 1994 and 2008 were included. Exclusion criteria were the intake of medication that might affect thyroid function and previous thyroid cancer or thyroid surgery.

RESULTS

The mean TSH value was comparable between patients with PTMCs (1.40 +/- 0.92 mLU/L, 95% CI = 1.07-1.72) and the control group (1.43 +/- 1.44 mLU/L; 95% CI = 1.04-1.82, p = 0.912). There was a positive trend in correlation between nodule size and TSH levels in patients with PTMC (p = 0.066).

CONCLUSIONS

TSH is not elevated in subjects with PTMCs, indicating that it is not likely involved in the de novo oncogenesis of these small cancers. However, TSH might rather play a role in the progression of preexisting PTMCs.